1. Field of the invention
The invention relates to a pillar structure, and more particularly, to a pillar structure applied to a body of an automobile.
2. Description of the Related Art
FIG. 20 shows an example (WO92/11158) of a pillar structure applied to a body of an automobile.
A center pillar 70 is made of an extruded material or casting material. The center pillar 70 is provided with members 72, 74, 76, 78, 80 and 82 which are cut such that their heights are different from one another stepwisely.
In the aforementioned structure, the number of parts constituting the pillar is increased and thus, a weight of the pillar itself is adversely increased. When a function part (such as a shoulder belt anchor) is mounted to the center pillar 70, it is necessary to secure mounting means (such as a bracket) by welding or the like for supporting the function part to the center pillar 70. As a result, the number of parts is further increased and a mass thereof is increased.
EP 0 836 983 A2 discloses a pillar structure capable of incorporating the function part within a cross section of a pillar, and having a horizontal cross section opened toward the inner side of a passenger compartment.
When a load such as a collision is applied to such a pillar from its side, it is difficult to deform the pillar in a desired deformation mode, and impact energy can not be absorbed efficiently in some cases.
Furthermore, EP 0 952 067 A2 shows a center pillar for a vehicle having an open cross-section over its whole length, wherein an opening thereof is open towards the passenger compartment. Reinforcing ribs are provided inside the cross-section of the pillar. In case of a side impact, the sharp edges will approach passengers, thus increasing risk of injury. Accordingly additional cover means have to be provided to maintain security of the passengers
It is an object of the invention to provide a pillar structure capable of saving weight and enhancing absorbing effect of impact energy. This object is solved with a pillar having the features of claim 1.